In general, “panoramic imaging” refers to the ability for showing a visual scene with a relatively high degree, or “wide,” field of view. For example, panoramic imaging may involve capturing images showing a 360° field of view around a particular object.
While a field of view of a single camera may be increased to some extent to capture a panoramic scene, generally multiple cameras are needed to capture true high-resolution panoramic video. A typical way to perform panoramic imaging involves the use of a “fixed head” immersive video sensor. As shown in FIG. 1, this type of video sensor 10 is formed of multiple video cameras 12, 14, 16, 18, 20, 22. The video cameras 12, 14, 16, 18, 20, 22 are positioned close to each other around a fixed head 24 (the fixed head 24 preferably being as small as possible to allow the video cameras 12, 14, 16, 18, 20, 22 to be positioned closer to each other) such that they collectively have a 360° field of view around the fixed head 24. Typically, the video cameras 12, 14, 16, 18, 20, 22 are positioned close to each other and set to each have a 60-62° field of view (thus, allowing for slight overlap among the edges of images captured by the video cameras 12, 14, 16, 18, 20, 22). Thus, in general, a fixed head immersive video sensor, such as one of the type shown in FIG. 1, can be used to capture horizontally an/or vertically panoramic images from a single, fixed point in space.
Deploying a fixed head immersive video sensor involves positioning the sensor on the exterior of an object from which a panoramic image is desired. For example, should one wish to capture a panoramic image around a vehicle (for, for example, safety or surveillance purposes), the fixed head immersive video sensor could be attached to the vehicle roof, at some height therefrom, in order to minimize or remove any visual obstructions that might otherwise be caused by the vehicle itself. However, such exterior deployment of the fixed head immersive video sensor may subject the sensor to, for example, adverse weather conditions (e.g., humidity, rain, wind), travel conditions (e.g., wind at high speeds, height clearance, drag), and structural issues (e.g., if the vehicle is very wide and/or long, the sensor will have to be disposed at a greater height to avoid visual obstructions caused by the vehicle, thereby requiring increased attention and potential expense to the mechanism or structure supporting the sensor above the vehicle). Moreover, for example, in a military application in which a fixed head immersive video sensor is used for enemy surveillance, the exteriorly positioned sensor represents a fairly unprotected point of attack by which the enemy can bring down the entire surveillance system with a single shot.
Alternatively, a fixed head immersive video sensor could be positioned inside the object, but this often introduces obstructions into the field of view. For example, if a fixed head immersive video sensor is positioned in the interior of a vehicle, the roof, doors, dashboard, seats, occupants, and other opaque objects within the vehicle would obstruct one or more portions of the cumulative field of view of the fixed head immersive video sensor.